Rayzon: Scaling N-Type TOPCon Manufacturing to Multi-Gigawatt Levels

For Rayzon, scaling TOPCon to multi-gigawatt levels is less about expansion and more about control. At smaller capacities, inefficiencies are manageable. At 5–10 GW scale, the same inefficiencies directly affect output, cost, and reliability in a significant way.

June 02, 2026. By News Bureau

Tags:

articles

The shift from P-type to N-type in solar manufacturing is already underway, and TOPCon has emerged as the most practical path for large-scale adoption. But there is a difference between installing TOPCon capacity and actually running it efficiently at scale. That difference is where most of the complexity lies.

For a company like Rayzon, scaling TOPCon to multi-gigawatt levels is less about expansion and more about control. At smaller capacities, inefficiencies are manageable. At 5–10 GW scale, the same inefficiencies directly affect output, cost, and reliability in a significant way.
TOPCon cells require the formation of an ultra-thin tunnel oxide layer, typically in the range of 1–2 nanometers. This layer is critical because it allows electrons to pass while reducing recombination losses. The challenge is that maintaining this level of precision consistently across millions of wafers is not easy. Even slight deviations in thickness or contamination during processing can reduce cell performance. When production runs into gigawatts, these small variations turn into measurable losses.

This is why process control becomes central. In TOPCon manufacturing, the margin for error is smaller than in PERC. Temperature uniformity, deposition quality, and surface cleanliness all have to be tightly managed. It is not enough to achieve high efficiency once; the factory must deliver the same output across every batch. That is what defines real scale.

Another critical factor is yield. Yield is the percentage of good output compared to total production. In TOPCon lines, yield losses can come from multiple points—wafer breakage, non-uniform passivation, metallisation defects, or contamination. At a few hundred megawatts, yield losses are tolerable. At multi-GW scale, even a small drop in yield can increase cost per watt and reduce margins. This makes yield management one of the most important operational priorities.

Equipment plays a role, but it is not the deciding factor. Two factories with similar machines can produce very different results. The difference comes from process tuning, maintenance discipline, and how quickly issues are identified and corrected. TOPCon requires tighter integration between engineering and operations teams because feedback loops need to be faster. Problems cannot be allowed to continue for long production cycles.

Material quality also becomes more important. N-type wafers have advantages such as no light-induced degradation, but they require better control during processing. Variations in wafer resistivity or surface condition can affect passivation quality. Similarly, encapsulation materials, glass, and metallisation pastes need to be consistent. Any fluctuation in input quality shows up directly in output performance. This is one reason why manufacturers scaling TOPCon often move toward backward integration—to reduce dependence on external variability.

Module design is also evolving along with cell technology. Larger formats like 210 mm or 210R are being used to increase module wattage beyond 600 W. This helps reduce balance-of-system costs for projects, which is important for utility-scale installations. However, larger formats introduce mechanical and handling challenges during manufacturing. Maintaining cell integrity, alignment, and lamination quality becomes more demanding. Scaling these formats requires careful optimisation of production lines.

TOPCon modules are typically bifacial, meaning they generate power from both the front and back sides. This can increase energy yield in real-world conditions, especially in installations with reflective surfaces. However, bifacial performance depends not only on installation conditions but also on manufacturing consistency. Variations in cell quality or glass transparency can lead to uneven performance. So while bifaciality offers a clear advantage, it also adds another layer of quality dependence.

Cost reduction in TOPCon manufacturing does not come only from increasing capacity. It comes from stabilising the process. When production runs are stable, with high yield and low defect rates, cost per watt naturally decreases. If processes are unstable, scaling can actually increase losses because more defective output is produced. This is why companies focusing on TOPCon scaling prioritise process stability over rapid expansion alone.

At multi-gigawatt scale, data becomes an important asset. Every stage of production generates data—temperature profiles, deposition rates, defect patterns, efficiency variations. The ability to analyse this data and act on it quickly determines how efficiently a plant runs. Over time, this creates a learning curve advantage. A manufacturer producing at higher volumes gains more operational insight, which helps improve performance further. This is one of the key benefits of scaling early and aggressively.

Another important aspect is reliability. Solar projects are long-term investments, often expected to perform for 25 years or more. For manufacturers, this means that scaling production must not compromise long-term module performance. Degradation rates, PID resistance, and encapsulation quality must remain consistent. Any compromise at the manufacturing stage can lead to performance issues later, which affects credibility in global markets.

For Rayzon, scaling TOPCon to multi-GW levels indicates a shift toward more controlled and process-driven manufacturing. It reflects a move away from simply increasing capacity to focusing on how that capacity performs. The transition also aligns with global demand trends, where buyers are increasingly looking for higher efficiency, better energy yield, and reliable long-term performance.

In practical terms, scaling TOPCon successfully requires four things to work together: stable processes, high yield, consistent material quality, and strong data-driven decision-making. If any one of these is weak, scaling becomes inefficient. If all of them are aligned, scale becomes a real advantage.

The industry is moving in this direction, but execution is uneven. Some manufacturers have installed TOPCon lines but are still optimising yields. Others are focusing on improving consistency before expanding further. The difference between these approaches will become clearer over time as large-scale performance data becomes available.

For now, what stands out is that TOPCon is no longer just a technology upgrade. At multi-gigawatt scale, it becomes a test of manufacturing capability. The companies that manage to control their processes, maintain high yields, and deliver consistent performance will define the next phase of solar manufacturing.

- Chirag Nakrani, Founder and MD, Rayzon Solar